The present invention relates generally to mobile communications systems, and more specifically to a mobile station which transmits burst signals at such times that the round-trip propagation delay time of signals between each cell site and the mobile station is compensated.
In time division multiple access digital communications systems, the propagation delay time of a signal sent from a cell site and the same amount of delay time involved with a signal sent in response to it from a mobile station are the factor that must be taken into account to allow the cell site to precisely detect signals from preassigned timeslots. Conventional mobile stations are provided with a plurality of delay elements which are controlled by a detected propagation delay time in such a manner that the round-trip propagation delay time is compensated. However, the operating performance of such delay elements are sensitive to ambient temperatures and variabilities exist among the delay times of different mobile stations. Difficulty thus arises to precisely control and maintain the propagation delay time factor for each mobile station.